Extrusion Coating Composition

ABSTRACT

Multimodal polyethylene compositions are provided. Extrusion compositions including the multimodal polyethylene are provided. The extrusion composition further include a high pressure low density polyethylene and optionally other additives and/or polyethylenes. Extruded articles made from the polyethylene extrusion compositions are also provided.

BACKGROUND OF THE INVENTION

This invention relates to novel multimodal polyethylenes, polyethyleneextrusion compositions comprising low density polyethylene and themultimodal polyethylene, and also to extruded articles made from thepolyethylene extrusion compositions.

Low density polyethylene (LDPE) made by high-pressure polymerization ofethylene with free-radical initiators as well as high densitypolyethylene (HDPE), linear low density polyethylene (LLDPE) and ultralow density polyethylene (ULDPE) made by the copolymerization ofethylene α-olefins with Ziegler-Natta and/or single site metallocenecatalysts at low to medium pressures have been used, for example: (i) toextrusion coat substrates such as paper board, paper, and/or polymericsubstrates; (ii) to prepare extrusion cast film for applications such asdisposable diapers and food packaging; and (3) to prepare extrusionprofiles such as wire and cable jacketing. Hereinafter, traditionalHDPE, LLDPE and ULDPE resins, comprising linear and substantially linearpolyethylene resins, are collectively referred to as linearpolyethylene. Although LDPE generally exhibits excellent extrusionprocessability and high extrusion drawdown rates, LDPE extrusioncompositions lack sufficient abuse resistance and toughness for manyapplications.

The density limitations of LDPE resins, approximately 0.915-0.935 g/cc,hinders their use unblended when lower heat seal characteristics areneeded, or for higher density applications, such as release papercoating, photographic paper coating where higher modulus is needed. Forextrusion coating and extrusion casting purposes, efforts to improveproperties by providing LDPE compositions having high molecular weights(i.e., having melt index, I₂, less than about 2 g/10 min) are noteffective since such compositions inevitably have too much melt strengthto be successfully drawn down at high line speeds. While ethylenecopolymers with functionalized olefins, such as vinyl acetate, offerlower heat seal temperatures, the chemical properties of such resinsmake them unsuitable for many uses. No known method to prepare a LDPEwith density above about 0.935 has been disclosed. Thus applicationsrequiring such higher densities rely on linear resins, usually blendedwith LDPE to improve the coating performance, but usually with sacrificeof the desired physical properties.

While HDPE, LLDPE and ULDPE extrusion compositions offer improved abuseresistance, toughness properties and barrier resistance (against, forexample, moisture and grease permeation), these linear ethylene polymerscannot be extruded or drawn down at high take-off rates and they areknown to exhibit relatively poor extrusion processability in the form ofhigh neck-in, draw resonance and high motor load.

The ultimate extrusion drawdown rate of ethylene α-olefin interpolymersis limited (at otherwise practical extrusion line speeds) by the onsetof a melt flow instability phenomena known as draw resonance rather thanbeing limited by melt tension breaks due to “strain hardening” whichoccurs at higher line speeds and is typical for LDPE and other highlybranched high pressure ethylene polymers such as, for example,ethylene-acrylic acid (EAA) copolymers and ethylene vinyl acetate (EVA)copolymers, herein referred to as functionalized LDPE resins.

Linear low density polyethylene (LLDPE) is typically a copolymer ofethylene and an α-olefin of 3 to 12 carbon atoms, preferably 4 to 8carbon atoms (for example, 1-butene, 1-octene, etc.), that hassufficient α-olefin content to reduce the density of the copolymer to adensity of from 0.915 to 0.935 g/cc, the density range available forLDPE. LLDPE resins exhibit improved performance over LDPE in many areas,including improved abuse resistance, toughness properties, sealantproperties, range of modulus, barrier resistance (against, for example,moisture and grease permeation). However, in general, linear ethylenepolymers exhibit unacceptably high neck-in and draw resonance resultingin relatively poor extrusion processability compared to pure LDPE.Consequently, LLDPE resins are generally considered unacceptable in theextrusion coating industry and are blended with LDPE in commercialapplications to improve processability while benefiting from thesuperior range of physical properties of LLDPE. However, addition ofLDPE resins does have some negative impact on the performance propertiesof LLDPE.

Several compositions containing LDPE blended with linear polyethyleneresins have been disclosed. For example, U.S. Pat. No. 5,582,923discloses compositions with 5% to 20% LDPE, I₂<6 g/10 minutes, andlinear density 0.85-0.94. Similarly, U.S. Pat. No. 5,773,155 and EP0792318 disclose substantially linear polyethylene blended with up to25% LDPE. WO 2005/023912 discloses an extrusion composition containing aminimum of 10% LDPE wherein the substantially linear polyethylenecomponent has a melt index>20 g/10 min. The compositions disclosed inthese references can be blended as part of the powder pelletizationstage in the gas phase process for manufacturing linear polyethyleneresins. However, not all manufacturing installations have such processcapability. In general, these compositions cannot be prepared in thesolution process for manufacturing linear polyethylene resins prior topelletization because the capability to feed the required amounts ofLDPE is not available or would require unacceptable reduction in reactorrate. Thus, these blends must be made subsequent to pelletization atsubstantial cost, (e.g., costs related to reheating the polymers andtransportation).

Often solution process linear polyethylene plants are designed with thecapability to side-arm a quantity of material into the molten polymerflow prior to pelletization. The maximum quantity that may be added byside-arm addition is generally less than 20% of the polymer flow andmore often <6% of the polymer flow. This side arm addition capability isgenerally utilized for addition of various additives to the polymer suchas anti-oxidants, slip agents and the like.

Thus, there is a need for linear polyethylene compositions of a widerange of densities, which when blended with LDPE resin, exhibitacceptable coating behavior and wherein the blend comprises <20% LDPE ofthe total resin weight and preferably <6% LDPE.

Another need arises from the limited availability of autoclave LDPE.Although autoclave LDPE is generally preferred for extrusion coatingprocesses, there is much wider availability of tubular LDPE compared toautoclave LDPE. Tubular LDPE, however, tends to cause the formation ofsmoke during the extrusion coating process. Moreover, when blended withlinear polyethylene, greater amounts of tubular LDPE, compared toautoclave LDPE, are required to attain acceptable processability, e.g.,low neck-in and high drawdown rates. The amount of tubular LDPEgenerally needed to obtain acceptable extrusion processability is atleast 25% of the total resin when blended with known linear polyethyleneresins. Such large amounts of tubular LDPE cause substantial smokingduring extrusion and are often associated with wax build-up on variousparts of the extrusion equipment, such as rollers, resulting inundesirable equipment shut-down. To take advantage of the wideravailability of tubular polyethylene, it would be desirable to have alinear polyethylene composition that, when blended with less that 25%tubular LDPE by weight of the total resin, exhibits acceptable extrusionprocessability.

As described hereinafter, the present invention substantially fills theneed for ethylene polymer extrusion compositions having high linespeeds, high resistance to draw resonance and substantially reducedneck-in, comprising <20% autoclave LDPE of the total resin weight andpreferably <6% autoclave LDPE, and a method of making such compositions.Embodiments of the invention further fills the need for ethylene polymerextrusion compositions yielding acceptable extrusion coater performancecomprising tubular LDPE comprising 15% to 20% of the total resincomposition. The linear polyethylene resin component of embodiments ofthe present invention comprise a high molecular weight component havingsubstantial long chain branching and a low molecular weight componentand is referred to hereinafter as Multimodal polyethylene or MultimodalPE. The compositions of the present invention can be used in conjunctionwith known resin manufacturing and extrusion coating equipment andequipment modifications and the combined or synergistic benefits of thepresent invention and known solutions can also be realized.

SUMMARY OF THE INVENTION

Certain embodiments of the invention provide a polyethylene resincharacterized by: (a) M_(w)(abs)/M_(w)(RI)>1.05 and <1.6; (b)M_(z)(measured)/M_(z)(calc)>1.4 and <3.0 where M_(z)(calc) is calculatedfrom the measured I₂ according toM_(z)(calc)=1.5*10^((5.077-0.284*log 10(I) ² ⁾⁾; (c) I₂>8.0 g/10 minutesand <15.0 g/10 minutes; (d) CDF(RI fraction)>0.01 at a log 10(M_(w)) of5.5; and (e) density in the range 0.860-0.965 g/cc.

Other embodiments of the invention provide an extrusion compositionincluding from 80% to 98% Multimodal PE and 2% to 20% LDPE wherein theMultimodal PE is characterized by: (a) M_(w)(abs)/M_(w)(RI)>1.05 and<1.6; (b) M_(z)(measured)/M_(z)(calc)>1.4 and <3.0; (c) I₂>8.0 g/10minutes and <15.0 g/10 minutes; (d) CDF(RI fraction)>0.01 at a log10(M_(w)) of 5.5; and (e) density in the range 0.860-0.965 g/cc; and theLDPE is characterized by having a I₂ less than 10 g/10 min and greaterthan 0.2 g/10 min, and a M_(w)(abs)/M_(w)(RI)>2.0.

In particular embodiments of the invention, the extrusion compositionincludes from 91% to 97% Multimodal PE and 3% to 9% LDPE and furtherwherein the Multimodal PE is characterized by: (a) M_(w) (abs)/M_(w)(RI)>1.10 and <1.20; (b) M_(z)(measured)/M_(z)(calc)>1.5 and <2.5; (c)I₂>9.0 and <12.0; (d) CDF(RI fraction)>0.02 at a log 10(M_(w)) of 5.5;and (e) MWD>3.0 and <3.5; and the LDPE is characterized by having a I₂less than 1.0 g/10 min and greater than 0.3 g/10 min, and theM_(w)(abs)/M_(w)(RI) is >3.2.

Yet other embodiments of the invention provide an article comprising atleast one layer of an ethylene polymer extrusion composition, whereinthe extrusion composition comprises from 80% to 98% Multimodal PE and 2%to 20% LDPE. In certain aspects of the invention, the ethylene polymercomposition is in the form of an extrusion profile, an extrusion coatingonto a substrate or an extrusion cast film. In other aspects of theinvention, the article is an extrusion coating onto a substrate and thesubstrate is a woven or non-woven fabric. In yet other aspects, the atleast one layer of an ethylene polymer composition is a sealant layer,adhesive layer, abuse resistance layer, or release surface.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a table containing the operating conditions of the primaryreactor used to produce certain embodiments of the invention, namelyInventive Examples (“Inv. Ex.” or “IE”) 1-8 and Comparative Examples(“Comp. Ex.” or “CE”) A-B.

FIG. 2 is a table containing the operating conditions of the secondaryreactor used to produce certain embodiments of the invention, namelyInventive Examples (“Inv. Ex.” or “IE”) 1-8. Comparative examples (CE)A-B are single reactor resins and are not represented in FIG. 2.

FIG. 3 is a graphical illustration of the molecular weight distributionas measured by GPC evidencing the bi-modal MWD of two Multimodal PEsuseful in embodiments of the inventive composition and represent IE 2 &3 illustrating raw data plotted as “Light Scattering Response(=MW*Concentration) vs. Elution Volume.

FIG. 4 shows the normalized data of FIG. 3.

FIG. 5 shows the CDF(RI) plots for inventive and comparative examplesdiscussed herein. In the caption of FIG. 5, the term “CE” is used torefer to comparative examples and the term “IE” is used to refer toinventive examples.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 1. Definitions

The term “haul-off,” as used herein, means the speed at which asubstrate is moving, thus stretching or elongating a molten polymerextrudate.

The term “neck-in,” as used herein, is the difference between the diewidth and the extrudate width on the fabricated article. The neck-invalues reported herein are determined at a haul off rate of 440feet/minute which yields a 1 mil coating thickness at an extrusion rateof approximately 250 lbs/hr using a 3.5-inch diameter, 30:1 L/Dextrusion coater equipped with a 30 inch wide die deckled to 24 inchesand having a 25-mil die gap, at a temperature of about 600° F., whereas“Drawdown” is defined as the haul-off speed at which the molten polymerbreaks from the die or the speed at which edge instability. Data is alsoreported at a haul off rate of 880 feet/minute under similar processingconditions which yields a coating thickness of 0.5 mil.

The term “polymer,” as used herein, refers to a polymeric compoundprepared by polymerizing monomers, whether of the same or a differenttype. The generic term polymer thus embraces the term “homopolymer”,usually employed to refer to polymers prepared from only one type ofmonomer as well as “copolymer” which refers to polymers prepared fromtwo or more different monomers.

The term “LDPE,” as used herein, may also be referred to as “highpressure ethylene polymer” or “highly branched polyethylene” and isdefined to mean that the polymer is partly or entirely homopolymerizedor copolymerized in autoclave or tubular reactors at pressures above14,500 psi (100 MPa) with the use of free-radical initiators, such asperoxides (see for example U.S. Pat. No. 4,599,392, herein incorporatedby reference).

The term “functionalized polyethylene” means a polyethyleneincorporating at least one functional group in its polymer structure.Exemplary functional groups may include, for example, ethylenicallyunsaturated mono- and di-functional carboxylic acids, ethylenicallyunsaturated mono- and di-functional carboxylic acid anyydrides, saltsthereof and esters thereof. Such functional groups may be grafted to anethylene homopolymer or an ethylene-α-olefin interpolymer, or it may becopolymerized with ethylene and an optional additional comonomers toform an interpolymer of ethylene, the functional comonomer andoptionally other comonomer(s).

The term “long chain branching” or “LCB,” as used herein means a chainlength of at least 6 carbons, above which the length cannot bedistinguished using ¹³C nuclear magnetic resonance spectroscopy. Thelong chain branch can be as long as about the same length as the lengthof the polymer backbone to which it is attached.

The term “molecular weight distribution” or “MWD,” as used herein, isdefined as the ratio of weight average molecular weight to numberaverage molecular weight (M_(w)/M_(n)). M_(w) and M_(n) are determinedaccording to methods known in the art using conventional GPC.

The ratio M_(w) (absolute)/M_(w) (GPC) or “Gr,” as used herein, isdefined wherein M_(w) (absolute) is the weight average molecular weightderived from the light scattering area at low angle (such as 15 degrees)and injected mass of polymer and the M_(w) (GPC) is the weight averagemolecular weight obtained from GPC calibration. The light scatteringdetector is calibrated to yield the equivalent weight average molecularweight as the GPC instrument for a linear polyethylene homopolymerstandard such as NBS 1475.

2. Description of the Composition

Embodiments of the inventive extrusion composition are blends of one ormore multimodal polyethylene resins, each comprising a high molecularweight component with substantial long chain branching and at least onelower molecular weight polyethylene resin, blended with one or more LDPEresins or blends of LDPE and one or more functionalized LDPE resins,optionally with additional polymers, such as minor amounts ofpolypropylene. Whereas embodiments of the invention may comprise up to20% LDPE, one preferred embodiment comprises about 90% of at least oneMultimodal PE component based on the total weight of the composition. Inanother preferred embodiment, the composition comprises at least about94% of the Multimodal PE component, and in a more preferred embodimentthe composition comprises 96% of the Multimodal PE component.

Embodiments of the inventive composition also contain from 2% to 20%,preferably from 4% to 10%, based on the total weight of the composition,of at least one LDPE. It should be understood that the total amount ofMultimodal PE and LDPE does not necessarily have to equal 100%.

Without being bound to any particular theory, it is presently believedthat the low neck-in provided by the inventive compositions, despite thelow levels of LDPE present, is due to the molecular architecture of theMultimodal PE component of the composition. Without intending to bebound to any particular theory, it is believed that the high molecularweight, highly branched component of the Multimodal PE leads to theunique balance of processability and extrudability seen in embodimentsof the inventive polyethylene extrusion compositions.

3. LDPE

The preferred LDPE for use in the present invention has a density offrom 0.916 g/cc to 0.935 g/cc. All individual values and subranges from0.916 to 0.935 g/cc are included herein and disclosed herein; forexample, the density can be from a lower limit of 0.916 g/cc; 0.917g/cc, or 0.918 g/cc to an upper limit of 0.922 g/cc, 0.927 g/cc or 0.935g/cc. For example, the LDPE may have a density in the range of from0.917 g/cc to 0.922 g/cc or in the alternative of from 0.918 g/cc to0.934 g/cc. The preferred LDPE for use in the present invention has aMelt Index (I₂) of from 0.2 g/10 minutes to 10 g/10 minutes. Allindividual values and subranges from 0.2 g/10 minutes to 10 g/10 minutesare included herein and disclosed herein; for example, the melt index(I₂) can be from a lower limit of the melt index (I₂) can be from alower limit of 0.3 g/10 minutes, 0.4 g/10 minutes, or 0.5 g/10 minutesto an upper limit of 1 g/10 minutes, 2 g/10 minutes, 3 g/10 minutes, or7 g/10 minutes. For example, the LDPE may have a melt index (I₂) in therange of 0.3 g/10 minutes to 3 g/10 minutes; or in the alternative, theLDPE may have a melt index (I₂) in the range of 0.4 g/10 minutes to 7g/10 minutes. In some embodiments, the melt index (I₂) of the LDPE maybe greater than about 0.25 g/10 minutes, or alternatively, more than 0.3g/10 minutes. In some embodiments, the melt index (I₂) of the LDPE maybe less than 3 g/10 min, or alternatively, less than about 0.7 g/10 min.While LDPE with a M_(w)/M_(n)>5.0 as measured by conventional GPC may beused in embodiments of the inventive composition, preferred embodimentsof the composition include a LDPE having a M_(w)/M_(n) as measured byconventional GPC greater than about 10. The preferred LDPE also may havea M_(w) (abs)/M_(w) (GPC) ratio (or GR value) of greater than about 2.0with Gr values greater than 3 or 3.5 preferably used in someapplications. As measured by triple-detector GPC, the M_(w) (abs)/M_(w)(RI) is >2.0, more preferably >3.0 and most preferably >3.3. The mostpreferred LDPE may be made in the autoclave process under single phaseconditions designed to impart high levels of long chain branching asdescribed in PCT patent publication WO 2005/023912, the disclosure ofwhich is incorporated herein.

The composition of some embodiments of the present invention may alsoinclude LDPE/LDPE blends where one of the LDPE resins has a relativelyhigher melt index and the other has a lower melt index and is morehighly branched. The component with the higher melt index can beobtained from a tubular reactor, and a lower MI, higher branched,component of the blend may be added in a separate extrusion step orusing a parallel tubular/autoclave reactor in combination with specialmethods to control the melt index of each reactor, such as recovery oftelomer in the recycle stream or adding fresh ethylene to the autoclavereactor, or any other methods known in the art for controlling the meltindex obtained in each reactor. The melt index (I₂) of a tubular LDPEfor use in the inventive composition is preferably in the range 0.2 g/10minutes-5.0 g/10 minutes, and more preferably 0.2 g/10 minutes to 1.0g/10 minutes and most preferably 0.2 g/10 minutes to 0.5 g/10 minutes.Two phase autoclave LDPE resins may also be used, having a melt index(I₂) range of 0.2 g/10 minutes-5.0 g/10 minutes and more preferably 0.2g/10 minutes to 1.0 g/10 minutes and most preferably 0.2 g/10 minutes to0.5 g/10 minutes.

Suitable high pressure ethylene polymer compositions for use inpreparing embodiments of the inventive extrusion composition include lowdensity polyethylene (homopolymer), ethylene copolymerized with at leastone α-olefin e.g. butene, and ethylene copolymerized with at least oneα,β-ethylenically unsaturated comonomer, e.g., acrylic acid, methacrylicacid, methyl acrylate and vinyl acetate. One suitable technique forpreparing useful high pressure ethylene copolymer compositions isdescribed in U.S. Pat. No. 4,599,392, the disclosure of which isincorporated herein by reference.

While both high pressure ethylene homopolymers and copolymers arebelieved to be useful in the invention, homopolymer polyethylene isgenerally preferred.

4. Multimodal PE

Multimodal PE, as used herein, includes linear and substantially linearpolyethylene resins. The Multimodal PE used in embodiments of theinvention may have a density of from 0.860 to 0.965 g/cc. All individualvalues and subranges from 0.860 to 0.965 g/cc are included herein anddisclosed herein; for example, the density can be from a lower limit of0.860 g/cc, 0.875 g/cc, 0.900 g/cc, 0.905 g/cc, or 0.910 g/cc to anupper limit of 0.965 g/cc, 0.960 g/cc, 0.950, 0.940, or 0.930 g/cc. Forexample, the LDPE may have a density in the range of from 0.875 g/cc to0.940 g/cc or in the alternative in the range from 0.905 g/cc to 0.965g/cc. The Multimodal PE can be made via gas-phase, solution-phase orslurry polymerization or any combination thereof, using any type ofsingle reactor or a combination of two or more reactors in any type ofreactor or reactor configuration known in the art. The Multimodal PEutilized in preferred embodiments of the inventive extrusion compositionis made in the solution process operating in either parallel or seriesdual reactor mode.

Multimodal PE made via dual reactor mode comprises a higher melt index(I₂) (or low molecular weight) component made in one reactor with alower melt index (I₂) (or high molecular weight) component made in asecond reactor, wherein (log₁₀ higher melt index component)−(log₁₀ lowermelt index component) is greater or equal to 2.0. In the embodiments,the high molecular weight portion contains long chain branching. The lowmolecular weight component in such a dual reactor Multimodal PE can bemade with either a molecular catalyst such as described herein, or aheterogenous catalyst such as a Zeigler/Natta catalyst, whereas the highmolecular weight portion may be prepared with a molecular catalyst.

The density of the Multimodal PE is limited only by the theoreticallimits, and can be selected as desired for the intended end-useapplication. The preferred copolymer for the Multimodal PE includes anyC₃-C₂₀ alpha-olefin, although for many applications 1-hexene and1-octene are preferred. Terminal dienes, including butadiene and highercarbon number dienes can also be used to make the Multimodal PE used inembodiments of the inventive composition. 1,9decadiene is used incertain preferred embodiments.

Multimodal PE used in preferred embodiments of the inventivecompositions comprises a high molecular weight (HMW) component, wherethe HMW component contains substantial long chain branching.

The preferred melt index (I₂) for the Multimodal PE portion of theinventive composition is in the range 5-15 g/10 min. All individualvalues and subranges from 5 to 15 g/10 min. are included herein anddisclosed herein; for example, the density can be from a lower limit ofthe melt index (I₂) can be from a lower limit of 5 g/10 minutes, 6 g/10minutes, or 7 g/10 minutes to an upper limit of 10 g/10 minutes, 11 g/10minutes, 13 g/10 minutes, or 15 g/10 minutes. For example, theMultimodal PE may have a melt index (I₂) in the range of 5 to 13 g/10minutes; or in the alternative, the Multimodal PE may have a melt index(I₂) in the range of 7 to 11 g/10 minutes. The I₁₀/I₂ ratio of theMultimodal PE may be greater than or equal to 7.0. In alternativeembodiments, the ratio I₁₀/I₂ may be greater than or equal to 8 while inother embodiments the ratio I₁₀/I₂ may be greater than 10. Multimodal PEresin includes more than one component, then at least one of suchMultimodal PE components preferably is a high molecular weight polymerwith substantial long chain branching (the HMW-LCB component) within theconstraints of the process and with the following constraints withrespect to the totality of the Multimodal PE resin:

-   -   a. M_(w)(Abs)/M_(w)(RI)>1.05 and <1.6;    -   b. M_(z)(measured)/M_(z)(calculated)>1.4 and <3.0 where        M_(Z)(calculated) is calculated from the measured MI according        to M_(Z)(calculated)=1.5*10^((5.077-0.284*log 10(I) ² ⁾⁾:    -   c. I₂>8.0 g/10 minutes and <15.0 g/10 minutes; and    -   d. CDF(RI fraction)>0.01 at a log 10(M_(w)) of 5.5.

The HMW-LCB component of the Multimodal PE preferably comprises from 15%to 35% by weight of the total Multimodal PE resin weight, preferably 20%to 30%, and most preferably 23% to 27%. The HMW-LCB component of theMultimodal PE is manufactured in such a way as to introduce as much LCBas possible in the solution process. This entails running the solutionprocess under conditions which favor the formation of vinyl-terminatedmacromers (high reaction temperature and/or utilizing a catalyst whichfavors this mode of termination) and which favors the incorporation ofthese macromers (low ethylene concentrations and/or utilizing a catalystwhich favors incorporation of these macromers). Additionally, utilizinga diene as a comonomer is useful for increasing the branching in thiscomponent. Details of a solution process utilizing catalysts which favorlong chain branching can be found in WO 2007136506.

In another preferred aspect of the invention, the Multimodal PE containsonly the low and high I₂ components and thus contains bi-modal MWD asmeasured by GPC-LS. FIGS. 3 and 4 illustrate the bi-modal MWD ofexemplary Multimodal PE resins of the present invention. Thus, such acomposition is preferably made in a two stage solution reactor process.In alternative embodiments of the invention, the Multimodal PE resin maybe made in a single reactor with two or more different catalysts,selected to yield widely different molecular weight resins under thesame reactor conditions or, in yet another alternative embodiment, madeby blending one or more high molecular weight and one or more lowmolecular weight components. This latter method is not preferred as itremoves the advantage of eliminating post-reactor blending. The use ofmultiple catalysts in one reactor, though possible, is not preferred asthe widely differing molecular weights required for the two componentsare more easily achieved in two separate reactors where the conditionscan be controlled to be favorable to the production of the neededmolecular weights. In manufacturing situations were ethylene andhydrogen are recycled from the end of the process and fed into thereactor in which the high molecular weight component is being made, itis preferred to remove the hydrogen by some means, includingcatalytically reacting it with the ethylene after gas separation fromthe polymer/solvent mixture to produce ethane or prior to separation ofthe ethylene and hydrogen from the solvent/alpha-olefin mixture.

The high molecular weight polymers containing the LCB are preferablymade with a molecular catalyst yielding resin with a maximum MWD of 3.0and capable of introducing LCB and building high molecular weight suchas described in patent applications WO2007/136497, WO2007/136506,WO2007/136495, WO2007/136496, 2007136494, the disclosures of which areincorporated herein. The low molecular weight components may be madewith any catalyst known in the art for making linear or substantiallylinear polyethylene. However a polymer with a MWD<2.2 is preferred. Morepreferred is a homogeneous comonomer distribution, in the case ofethylene-α-olefin comonomers. All typical and possible levels ofcomonomer content may be used in various embodiments of the inventionand are selected to suit selected reactor conditions and catalyst. Thus,various embodiment of the Multimodal PE utilized in the inventiveextrusion compositions exhibit the entire range of densities ofpolyethylene known in the art. The final density may be obtained by anyappropriate combination of density distributions among the components.The design of the composition with respect to density is dictated by theproperties required by the end-use application as is well understood inthe art.

Without being bound to any particular theory, it is presently believedthat the presence of LCB in the low molecular weight component(s) haslittle effect on the performance of the inventive compositions duringextrusion (i.e. motor-load, neck-in, draw-down, instabilities) and onthe properties of the extruded product and any level of LCB in the lowmolecular weight component(s) of the Multimodal PE is within the scopeof the invention.

Due to the relatively broad molecular weight distribution ofZeigler-Natta and chromium catalyzed polymers the low molecularcomponent(s) of the inventive compositions are preferably made with aMWD<2.2 using a molecular catalyst, such as a constrained geometrycatalyst or other catalyst capable of producing such a polymer, such asdescribed in U.S. Pat. Nos. 5,272,236; 5,278,272; 5,582,923; and5,733,155, and such as described in patent applications WO 2007136497,WO 2007136506, WO 2007136495, WO 2007136496, and WO 2007136494. This isbecause the large amount of low molecular weight molecules present whenbroad molecular weight distribution resins are used causes unacceptablesmoke during extrusion and high hexane extractables in the extrudedpolymer which may be unacceptable, especially in food contactapplications. When the polymer is made in the solution process it ispreferred that the catalyst used to make the high molecular weightcomponent can generate a high molecular weight product containing highlevels of LCB at a reactor temperature >190° C. and at acceptableefficiency. Such catalysts and methods of use described in WO2007136497, WO 2007136506, WO 2007136495, WO 2007136496, and WO2007136494.

5. Details of GPC Method Utilized Herein

In order to determine the GPC moments used to characterize the polymercompositions, the following procedure was used:

The chromatographic system consisted of a Waters (Millford, Mass.) 150 Chigh temperature chromatograph equipped with a Precision Detectors(Amherst, Mass.) 2-angle laser light scattering detector Model 2040. The15-degree angle of the light scattering detector was used for thecalculation of molecular weights. Data collection was performed usingViscotek (Houston, Tex.) TriSEC software version 3 and a 4-channelViscotek Data Manager DM400. The system was equipped with an on-linesolvent degas device from Polymer Laboratories (Shropshire, UK).

The carousel compartment was operated at 140° C. and the columncompartment was operated at 150° C. The columns used were 7 PolymerLaboratories 20-micron Mixed-A LS columns. The solvent used was 1,2,4trichlorobenzene. The samples were prepared at a concentration of 0.1grams of polymer in 50 milliliters of solvent. The chromatographicsolvent and the sample preparation solvent contained 200 ppm ofbutylated hydroxytoluene (BHT). Both solvent sources werenitrogen-sparged. Polyethylene samples were stirred gently at 160° C.for 4 hours. The injection volume used was 200 microliters and the flowrate was 1.0 milliliters/minute.

Calibration of the GPC column set was performed with 18 narrow molecularweight distribution polystyrene standards with molecular weights rangingfrom 580 to 8,400,000 which were arranged in 5 “cocktail” mixtures withat least a decade of separation between individual molecular weights.The standards were purchased from Polymer Laboratories (Shropshire, UK).The polystyrene standards were prepared at 0.025 grams in 50 millilitersof solvent for molecular weights equal to or greater than 1,000,000, and0.05 grams in 50 milliliters of solvent for molecular weights less than1,000,000. The polystyrene standards were dissolved at 80° C. withgentle agitation for 30 minutes. The narrow standards mixtures were runfirst and in order of decreasing highest molecular weight component tominimize degradation. The polystyrene standard peak molecular weightswere converted to polyethylene molecular weights using the followingequation (as described in Williams and Ward, J. Polym. Sci., Polym.Let., 6, 621 (1968)).:

M _(polyethylene) =A×(M _(polystyrene))^(B)

where M is the molecular weight, A has a value of 0.41 and B is equal to1.0. A fourth order polynomial was used to fit the respectivepolyethylene-equivalent calibration points.

The total plate count of the GPC column set was performed with Eicosane(prepared at 0.04 g in 50 milliliters of TCB and dissolved for 20minutes with gentle agitation.) The plate count and symmetry weremeasured on a 200 microliter injection according to the followingequations:

PlateCount=5.54*(RV at Peak Maximum/(Peak width at ½ height))̂2, where RVis the retention volume in milliliters and the peak width is inmilliliters.  (1)

Symmetry=(Rear peak width at one tenth height−RV at Peak maximum)/(RV atPeak Maximum−Front peak width at one tenth height)  (2)

where RV is the retention volume in milliliters and the peak width is inmilliliters.

The Systematic Approach for the determination of multi-detector offsetswas done in a manner consistent with that published by Balke, Mourey,et. al (Mourey and Balke, Chromatography Polym. Chpt. 12, (1992))(Balke, Thitiratsakul, Lew, Cheung, Mourey, Chromatography Polym. Chpt.13, (1992)), optimizing dual detector log MW results from Dow broadpolystyrene 1683 to the narrow standard column calibration results fromthe narrow standards calibration curve using in-house software. Themolecular weight data was obtained in a manner consistent with thatpublished by Zimm (Zimm, B. H., J. Chem. Phys., 16, 1099 (1948)) andKratochvil (Kratochvil, P., Classical Light Scattering from PolymerSolutions, Elsevier, Oxford, N.Y. (1987)). The overall injectedconcentration used for the determination of the molecular weight wasobtained from the sample refractive index area and the refractive indexdetector calibration from a linear polyethylene homopolymer of 115,000molecular weight. The chromatographic concentrations were assumed lowenough to eliminate addressing 2^(nd) virial coefficient effects(concentration effects on molecular weight).

In order to monitor the deviations over time, which may contain anelution component (caused by chromatographic changes) and a flow ratecomponent (caused by pump changes), a late eluting narrow peak isgenerally used as a “marker peak”. A flow rate marker was thereforeestablished based on the air peak mismatch between the degassedchromatographic system solvent and the elution sample on one of thepolystyrene cocktail mixtures. This flow rate marker was used tolinearly correct the flow rate for all samples by alignment of the airpeaks. Any changes in the time of the marker peak are then assumed to berelated to a linear shift in both flow rate and chromatographic slope.

To facilitate the highest accuracy of a retention volume (RV)measurement of the flow marker peak, a least-squares fitting routine isused to fit the peak of the flow marker concentration chromatogram to aquadratic equation. The first derivative of the quadratic equation isthen used to solve for the true peak position. After calibrating thesystem based on a flow marker peak, the effective flow rate (as ameasurement of the calibration slope) is calculated as Equation 1. In ahigh-temperature SEC system, an antioxidant mismatch peak or an air peak(if the mobile phase is sufficiently degassed) can be used as aneffective flow marker. The primary features of an effective flow ratemarker are as follows: the flow marker should be mono-dispersed. Theflow marker should elute close to the total column permeation volume.The flow marker should not interfere with the chromatographicintegration window of the sample.

FlowRateEffective=FlowRateNominal*FlowMarkerCalibration/FlowMarkerObserved  (3)

The preferred column set is of 20 micron particle size and “mixed”porosity to adequately separate the highest molecular weight fractionsappropriate to the claims. The verification of adequate columnseparation and appropriate shear rate can be made by viewing the lowangle (less than 20 degrees) of the on-line light scattering detector onan NBS 1476 high pressure low density polyethylene standard. Theappropriate light scattering chromatogram should appear bimodal (veryhigh MW peak and moderate molecular weight peak) with approximatelyequivalent peak heights. There should be adequate separation bydemonstrating a trough height between the two peaks less than half ofthe total LS peak height. The plate count for the chromatographic system(based on eicosane as discussed previously) should be greater than32,000 and symmetry should be between 1.00 and 1.12.

6. Preparation of the Polymer Extrusion Composition

The preferred blends for making the polymer extrusion compositions ofthis invention can be prepared by any suitable means known in the artincluding tumble dry-blending, weigh feeding, solvent blending, meltblending via compound or side-arm extrusion, or the like as well ascombinations thereof. The inventive extrusion composition can also beblended with other polymer materials, such as polypropylene, highpressure ethylene copolymers such as ethylvinylacetate (EVA) andethylene acrylic acid and the like, ethylene-styrene interpolymers, solong as the necessary rheology and molecular architecture as evidencedby multiple detector GPC are maintained. The inventive composition canbe used to prepare monolayer or multilayer articles and structures, forexample, as a sealant, adhesive or tie layer. The other polymermaterials can be blended with the inventive composition to modifyprocessing, film strength, heat seal, or adhesion characteristics as isgenerally known in the art.

Both the LDPE and the Multimodal PE portions of the preferredcomposition can be used in a chemically and/or physically modified formto prepare the inventive composition. Such modifications can beaccomplished by any known technique such as, for example, byionomerization and extrusion grafting.

Additives such as antioxidants (e.g., hindered phenolics such asIrganox® 1010 or Irganox® 1076 supplied by Ciba Geigy), phosphites(e.g., Irgafos® 168 also supplied by Ciba Geigy), cling additives (e.g.,PIB), Standostab PEPQ™ (supplied by Sandoz), pigments, colorants,fillers, and the like can also be included in the ethylene polymerextrusion composition of the present invention, to the extent that theydo not interfere with the high drawdown and substantially reducedneck-in discovered by Applicants. These compositions preferably containno or only limited amounts of antioxidants as these compounds mayinterfere with adhesion to the substrate. The article made from or usingthe inventive composition may also contain additives to enhanceantiblocking and coefficient of friction characteristics including, butnot limited to, untreated and treated silicon dioxide, talc, calciumcarbonate, and clay, as well as primary, secondary and substituted fattyacid amides, chill roll release agents, silicone coatings, etc. Otheradditives may also be added to enhance the anti-fogging characteristicsof, for example, transparent cast films, as described, for example, byNiemann in U.S. Pat. No. 4,486,552, the disclosure of which isincorporated herein by reference. Still other additives, such asquaternary ammonium compounds alone or in combination withethylene-acrylic acid (EAA) copolymers or other functional polymers, mayalso be added to enhance the antistatic characteristics of coatings,profiles and films of this invention and allow, for example, thepackaging or making of electronically sensitive goods. Other functionalpolymers such as maleic anhydride grafted polyethylene may also be addedto enhance adhesion, especially to polar substrates. Yet other examplesof functionalized polyethylene that may optionally be added toembodiments of the extrusion compositions herein include: copolymers ofethylene and ethylenically unsaturated carboxylic acid such as acrylicacid and methacrylic acid; copolymers of ethylene and esters ofcarboxylic acid such as vinyl acetate; polyethylene grafted with anunsaturated carboxylic acid or a carboxylic acid anhydride, such asmaleic anhydride. Specific examples of such functionalized polyethylenemay include, ethylene/vinyl acetate copolymer (EVA), ethylene/acrylicacid copolymer (EAA), ethylene/methacrylic acid copolymer (EMAA), saltstherefrom (ionomer), various polyethylene grafted with maleic anhydride(MAH) such as MAH-grafted high pressure low density polyethylene,heterogeneously branched linear ethylene α-olefin interpolymers (whichhave commonly been referred to as linear low density polyethylene andultralow density polyethylene), homogeneously branched linear ethyleneα-olefin interpolymers, substantially linear ethylene α-olefininterpolymers, and HDPE.

Multilayered constructions comprising the inventive composition can beprepared by any means known including co-extrusion, laminations and thelike and combinations thereof. Moreover, compositions of this inventioncan be employed in co-extrusion operations where a higher drawdownmaterial is used to essentially “carry” one or more lower drawdownmaterials. In particular the compositions of this invention are wellsuited to carry a material of lower draw-down.

The ethylene polymer extrusion compositions of this invention, whetherof monolayer or multilayered construction, can be used to make extrusioncoatings, extrusion profiles and extrusion cast films as is generallyknown in the art. When the inventive composition is used for coatingpurposes or in multilayered constructions, substrates or adjacentmaterial layers can be polar or nonpolar including for example, but notlimited to, paper products, metals, ceramics, glass and variouspolymers, particularly other polyolefins, and combinations thereof. Forextrusion profiling, various articles can potentially be fabricatedincluding, but not limited to, refrigerator gaskets, wire and cablejacketing, wire coating, medical tubing and water piping, where thephysical properties of the composition are suitable for the purpose.Extrusion cast film made from or with the inventive composition can alsopotentially be used in food packaging and industrial stretch wrapapplications.

INVENTIVE AND COMPARATIVE EXAMPLES

The following examples illustrate some of the particular embodiments ofthe present invention, but the following should not be construed to meanthe invention is limited to the particular embodiments shown.

Multimodal PE resins used in Inventive Examples (“Inventive”) 1-8 andvarious non-inventive resins used in Comparative Examples(“Comparative”) A-C

Table 1 summarizes the I₂, I₁₀ and I₁₀/I₂ ratio of Multimodal PE resins1-8, made in dual reactor mode with a high molecular weight, long chainbranching component, and linear polyethylene resins comparative examplesA-C. Table 1 further indicates the catalysts used in preparation of theresins inventive examples 1-8 as well as the nominal polymer produced bythe high molecular weight catalyst as a percentage of total polymerweight.

Preparation of Polymers:

Ethylene-octene copolymers were prepared using two continuous stirredtank reactors (CSTR) connected in parallel. Each reactor ishydraulically full and set to operate at steady state conditions.Inventive Examples 1-8 were produced in dual reactors run in parallel,the conditions of which are tabulated in FIGS. 1 and 2. The primaryreactor sample is prepared by flowing monomers, solvent, catalyst,cocatalyst, and MMAO to the primary reactor according to the processconditions shown in FIG. 1. The secondary reactor sample is prepared byflowing a separate stream of monomers, solvent, catalyst, cocatalyst,and MMAO according to the process conditions shown in FIG. 2. The tworeactor streams are combined after the reactors and mixed, devolatilizedand pelletized together Comparitive examples A and B were prepared insingle reactor mode using just the primary reactor. The solvent for thepolymerization reactions is a hydrocarbon mixture (SBP 100/140)purchased from Shell Chemical Company and purified through beds of 13-Xmolecular sieves prior to use. Unless specified otherwise, all reagentswere handled under anaerobic conditions using standard procedures forthe handling of extremely air- and water-sensitive materials. Solventswere degassed and dried over molecular sieves prior to use.

TABLE 1A Inventive Catalyst: HMW % I₂ (g/10 I₁₀ (g/10 Ex. 1-8 HMW/LMW(nominal) minutes) minutes) I₁₀/I₂ 1 A/B 25 14.3 126 8.8 2 A/C 25 11.7123 10.5 3 A/C 35 11.2 146 13.1 4 D/C 25 12.7 125 9.9 5 D/C 35 11.4 14112.4 6 E/C 25 12.1 191 15.8 7 E/C 35 10.7 258 24.1 8 A + DDE/C 25 13.8101 7.3

TABLE 1B Comparative Catalyst: HMW % I₂ (g/10 I₁₀ (g/10 Ex. A-C HMW/LMW(nominal) minutes) minutes) I₁₀/I₂ A A * 11.2 86 7.7 B D * 19.9 132 6.6C — — 12.0 67 5.6 * Single component resins

For Inventive Ex. 8, 1,9-decadiene (shown as +DDE in Table 1A) was fedat a rate of 11.8 g/hr. The catalysts A, C-E utilized to produce resinsInventive Ex. 1-8 and Comparative Ex. A-B in Tables 1A and 1B are asfollows:

Catalyst A may be made using the process described in WO 2007136497 (andreferences therein). Catalyst B is a heterogeneous Ziegler-type catalystprepared substantially according to U.S. Pat. No. 4,612,300 (Ex. P) bysequentially adding to a volume of Isopar E, a slurry of anhydrousmagnesium chloride in Isopar E, a solution of EtAlCl₂ in hexane, and asolution of Ti(O-iPr)₄ in Isopar E, to yield a composition containing amagnesium concentration of 0.17M and a ratio of Mg/Al/Ti of 40/12/3. Analiquot of this composition containing 0.064 mmol of Ti was then treatedwith a dilute solution of Et₃Al to give an active catalyst with a finalAl/Ti ratio of 8/1. Catalyst C may be made using the process describedin U.S. Pat. No. 5,512,693. Catalyst D may be made using the processdescribed in WO 9849212. and Catalyst E may be made using the processdescribed in WO 9806727. The co-catalyst is bis(hydrogenatedtallowalkyl)methylammonium tetrakis(pentafluorophenyl)borate which canbe prepared using the process described in U.S. Pat. No. 5,919,983.Comparative Ex. C is a commercial homogeneous polyethylene resinavailable from ExxonMobil.

Melt index (I₂) was measured at 190° C. under a load of 2.16 kgaccording to ASTM D-1238-03. Melt index (I₁₀) was measured at 190° C.under a load of 10.0 kg according to ASTM D-1238-03.

Tables 2A and 2B summarize GPC data on the resins of Inventive Ex. 1-8and Comparative Ex. A-C illustrated in Tables 1A and 1B.

TABLE 2A Inventive M_(z)/ M_(z)/ M_(w) (abs)/ Ex. 1-8 M_(n) M_(w) M_(z)MWD M_(w) M_(z) (calc) M_(z) (calc) M_(w) (RI) 1 6,550 49,450 143,4007.550 2.900 84168 1.704 1.14 2 21,430 64,490 200,500 3.009 3.109 890042.253 1.16 3 18,560 60,360 174,700 3.252 2.894 90158 1.938 1.17 4 16,99060,660 199,000 3.570 3.281 87116 2.284 1.07 5 15,430 55,150 153,5003.574 2.783 89796 1.709 1.16 6 13,470 61,270 226,700 4.549 3.700 883062.567 1.09 7 6,370 54,640 227,300 8.578 4.160 91358 2.488 1.06 8 9,37047,770 138,700 5.098 2.903 84990 1.632 1.51

TABLE 2B Comparative M_(z)/ M_(z)/ M_(w) (abs)/ Ex. A-C M_(n) M_(w)M_(z) MWD M_(w) M_(z) (calc) M_(z) (calc) M_(w) (RI) A 31,020 51,130105,500 1.648 2.063 90204 1.170 1.23 B 21,680 48,590 80,700 2.241 1.66176620 1.053 1.13 C 20,740 52,320 93,800 2.52 1.79 88490 1.06 1.06

Tables 3A-3B summarize certain key parameters for the inventive exampleand comparative example resins in Tables 1A-1B.

TABLE 3A R = CDF (RI) Inventive F = M_(w) (Abs)/M_(w) Z = M_(z)/fraction at I₂ (g/10 Ex. 1-8 (RI) M_(z) (calc) log10 (M_(w)) = 5.5minutes) 1 1.14 1.704 0.0158 14.3 2 1.16 2.253 0.0361 11.7 3 1.17 1.9380.0266 11.2 4 1.07 2.284 0.0282 12.7 5 1.16 1.709 0.0188 11.4 6 1.092.567 0.0426 12.1 7 1.06 2.488 0.0361 10.7 8 1.51 1.632 0.0152 13.8

TABLE 3B F = M_(w) R = CDF (RI) Comparative (Abs)/M_(w) Z = M_(z)/fraction at I₂ (g/10 Ex. A-C (RI) M_(z) (calc) log10 (M_(w)) = 5.5minutes) A 1.23 1.170 0.0048 11.2 B 1.13 1.053 0.0008 11.0 C 1.06 1.060.0011 12.0

Each of the Multimodal PE resin Inventive Ex. 1-8 and resins ComparativeEx. A-C shown in Tables 1A-1B were used to prepare extrusion compositionblends. Each of the polyethylene Examples and Comparative Examples shownin Tables 1A-1B were blended with 4 wt % LDPE. The LDPE resin used inthe examples and comparative examples of Extrusion Compositions shown inTables 4A-4B is described, including a process for making the LDPEresin, in PCT patent publication WO 2005/023912. More specifically, theLDPE resin used is available from The Dow Chemical Company, as LDPE662i, (having an I₂ of 0.45 g/10 minutes, density of 0.919 g/cc, andM_(w)(abs)/M_(w)(GPC) of 3.5). Each of Extrusion Composition InventiveExamples 1-8 and Extrusion Composition Comparative Examples A-C inTables 4A-4B and 5A-5B were produced using the corresponding numberedMultimodal PE Inventive Ex. 1-8 and resins Comparative Ex A-Cillustrated in Tables 1A-1B.

Table 4A-4B provide the melt indexes (I₂) of the extrusion compositionblends following dry blending but prior to extrusion. Except for blendComparative Ex. C (which was both calculated and measured), I₂ wascalculated using the model:

log₁₀(MI)=f_LDPE*log₁₀(I ₂(LDPE))+f_Linear*log₁₀(I ₂(Linear))

MI=10̂log(I₂), where f_LDPE is the weight fraction of LDPE and f_Linearis the weight fraction of the linear resin, and wheref_LDPE+f_Linear=1.0.

TABLE 4A Inventive Ex. 1-8 I₂ (g/10 minutes) (calculated) 1 12.5 2 10.33 9.85 4 11.1 5 10.0 6 10.6 7 9.43 8 12.0

TABLE 4B I₂ (g/10 minutes) (calculated) − I₂ (gf/10 Comparative Ex. A-Cminutes) (measured) A 9.85 B 17.1 C 10.5-10.5

Tables 5A-5B summarize the processing properties of ExtrusionComposition Inventive Ex. 1-8 and Extrusion Compositions Comparative Ex.A-C wherein the Amps, Melt T (melt temperature in ° C., HP (horsepower)and Press (pressure) are coater operation parameters and wherein DD isdrawdown in ft/min).

TABLE 5A Extrusion Composition Neck-in Inventive (inches) at Melt TPress Ex. 1-8 440 fpm 880 fpm DD HP Amps (° C.) (psi) 1 4.375 4.0001500+ 35 126 313 1135 2 3.625 3.500 1250   20 75 319 863 3 3.750 3.7501275   22 78 318 766 4 3.500 3.375 1500+ 28 101 315 1105 5 4.000 4.1251500+ 15 55 320 588 6 3.625 3.625 1500+ 16 58 317 695 7 4.250 4.2501500+ 17 62 316 655 8 3.750 3.750 1500+ 26 94 316 937

TABLE 5B Extrusion Composition Neck-in Comparative (inches) at Melt TPress Ex. A-C 440 fpm 880 fpm DD HP s Amp (° C.) (psi) A 4.250 4.0001500+ 34 121 317 1227 B 4.500 4.125 1500+ 30 111 316 994 C 6.375 5.8751500   40 143 323 1803

1. A polyethylene resin characterized by: a. M_(w)(abs)/M_(w) (RI)>1.05and <1.6; b. M_(z)(measured)/M_(z)(calc)>1.4 and <3.0 where M_(z)(calc)is calculated from the measured I₂ according toM_(z)(calc)=1.5*10^((5.077-0.284*log 10(I) ² ⁾⁾; c. I₂>8.0 g/10 minutesand <15.0 g/10 minutes; d. CDF(RI fraction)>0.01 at a log 10(M_(w)) of5.5; and e. density in the range 0.860-0.965 g/cc.
 2. An extrusioncomposition comprising from 80% to 98% a multimodal polyethylene and 2%to 20% LDPE wherein the multimodal polyethylene is characterized by: a.M_(w)(abs)/M_(w)(RI)>1.05 and <1.6; b. M_(z)(measured)/M_(z)(calc)>1.4and <3.0 where M_(z)(calc) is calculated from the measured I₂ accordingto M_(z)(calc)=1.5*10^((5.077-0.284*log 10(I) ² ⁾⁾; c. I₂>8.0 g/10minutes and <15.0 g/10 minutes; d. CDF(RI fraction)>0.01 at a log10(M_(w)) of 5.5; and e. density in the range 0.860-0.965 g/cc; and theLDPE is characterized by having a I₂ less than 10 g/10 minutes andgreater than 0.2 g/10 minutes, and a M_(w)(abs)/M_(w)(RI)>2.0.
 3. Theextrusion composition of claim 2 wherein the composition comprises from91% to 97% multimodal polyethylene and 3% to 9% LDPE and further whereinthe multimodal polyethylene is characterized by: a. M_(w) (abs)/M_(w)(RI)>1.10 and <1.20; b. M_(z)(measured)/M_(z)(calc)>1.5 and <2.5; c.I₂>9.0 g/10 minutes and <12.0 g/10 minutes; d. CDF(RI fraction)>0.02 ata log 10(M_(w)) of 5.5; and e. MWD>3.0 and <3.5; and the LDPE ischaracterized by having a I₂ less than 1.0 g/10 minutes and greater than0.3 g/10 minutes, and the M_(w) (abs)/M_(w) (RI) is >3.2.
 4. An articlecomprising at least one layer of an ethylene polymer extrusioncomposition, wherein the extrusion composition comprises from 80% to 98%multimodal polyethylene and 2% to 20% LDPE wherein the multimodalpolyethylene is characterized by: a. M_(w)(abs)/M_(w) (RI)>1.05 and<1.6; b. M_(z)(measured)/M_(z)(calc)>1.4 and <3.0 where M_(z)(calc) iscalculated from the measured I₂ according toM_(z)(calc)=1.5*10^((5.077-0.284*log 10(I) ² ⁾⁾; c. I₂>8.0 g/10 minutesand <15.0 g/10 minutes; d. CDF(RI fraction)>0.01 at a log 10(M_(w)) of5.5; and e. density in the range 0.860-0.965 g/cc; and the LDPE ischaracterized by having a I₂ less than 10 g/10 minutes and greater than0.2 g/10 minutes, and a M_(w)(abs)/M_(w)(RI)>2.0.
 5. The article ofclaim 4, wherein the article is in the form of an extrusion profile, anextrusion coating onto a substrate or an extrusion cast film.
 6. Thearticle of claim 5 wherein the article is an extrusion coating onto asubstrate and the substrate is a woven or non-woven fabric.
 7. Thearticle of claim 4, wherein the at least one layer of an ethylenepolymer composition is a sealant layer, adhesive layer, abuse resistancelayer, or release surface.
 8. The article of claim 7 wherein the articleis a sealant layer and wherein the density of the multimodalpolyethylene is <0.915 g/cc.
 9. The article of claim 7 wherein thearticle is a release surface wherein density of the multimodalpolyethylene is >0.940 g/cc.